People with passive sleep delay have more severe depression and sleep problems than those with active sleep delays-a cross-sectional study after the COVID-19 pandemic

OBJECTIVE: This study was designed to investigate the effect of different types of sleep delay in depression and sleep characteristics after the pandemic. Meanwhile, risk factors for depression were also explored. METHODS: The survey was conducted in Wuhan from March 1 to May 30, 2021, and participants were recruited through a snowball process. A total of 1,583 people with sleep delays responded to the invitation, of which 1,296 were enrolled. Participants filled out a questionnaire including social demographics, sleep characteristics, Social Support Rating Scale (SSRS), Pittsburgh Sleep Quality Index (PSQI) and Patient Health Questionnaire-9 (PHQ-9). RESULTS: There were no significant differences in sex, social support and level of education between the two types of sleep delay (p = 0.961, p = 0.110, p = 0.090), but the average age of the passive sleep delay group was higher (p = 0.015). And most people with active sleep delay were caused by the use of electronic devices (73.6%), while most people with passive sleep delay were caused by work or study tasks (73.2%), with a significant difference between the two groups (p < 0.001). People who actively delayed sleep had more regular sleep (p < 0.001), better sleep quality and longer sleep duration (p < 0.001, p < 0.001). In addition, although they delayed sleep more frequently (p < 0.001), they had significantly lower depression degree than people who passively delayed sleep (p < 0.001). CONCLUSIONS: Passive sleep delays, usually caused by work or study, has higher levels of depression and more adverse sleep behaviors than active sleep delay. The findings help further understand the effects of delayed sleep and provide insight for people with delayed sleep to evaluate their own condition. Future studies are required to standardize and accurately classify sleep delay and further explore it.